not a fashion expert but i do spend a lot of time scrolling through depop and buying new clothes ! the best advice i can give is that a shirt with a little bit of spice can never go wrong, whether that’s a unique colour, an interesting pattern or a nice material. this shirt i bought is my go-to formalwear and i usually combo it with a pair of tux trousers or even some corduroys if im feeling experimental. shoe wise cant go wrong with a pair of browns (I can typically get away with wearing some brown docs for a formal event but you do whats appropriate). jacket not needed but certainly an option. hope the search goes well!